Anyone caught twice possessing corrosive substances without a good reason will automatically face a prison sentence of at least six months under government proposals to counter the threat of acid attacks. The “two strikes” rule would mirror the regime for those convicted of more than one knife possession offence.

In addition, online retailers face criminal proceedings under the proposals if they deliver knives to a buyer’s home, in a measure aimed at clamping down on the sale of blades to children and teenagers. The steps form part of a drive to tackle violent crime following a surge in offences recorded by police.

After a series of high-profile incidents, the government announced plans to create a new offence of possession of a corrosive substance in public without a good or lawful reason. Currently, corrosive substances are treated by prosecutors as offensive weapons, possession of which carries a maximum sentence of four years in prison.

The full Home Office consultation document, published on Saturday, reveals that the proposed crackdown will also see those convicted for a second time face a mandatory minimum sentence. The approach will be modelled on a system rolled out in 2015 for offenders repeatedly caught with knives.

The minimum sentences were introduced for those aged 16 and older who are convicted of a second or subsequent offence of possession of a knife or offensive weapon.

The punishment is at least six months’ imprisonment, which can include suspended terms for adults, while young offenders face a minimum four-month detention and training order.

Judges must impose the minimum sentence unless there are particular circumstances relating to the latest offence, the previous offence or the offender which would “make it unjust to do so in all the circumstances”.

The consultation document says it is not intended that “corrosive substance” will be defined in legislation, as the offence “must be flexible enough to cover a range of possible situations: from someone possessing a corrosive substance in a public place that if used as a weapon can leave life-changing injuries; through to someone using a less harmful corrosive substance which if used as a weapon can still be very unpleasant to the victim but the effect is not lasting”.

A new offence to stop the sale of acids and the most harmful corrosive substances to people younger than 18 is also being weighed up.

Police recorded 408 attacks using corrosive substances between November 2016 and April this year. “The use of corrosive substances as a weapon is centuries old, but whilst the number of offences is relatively small, we are concerned about its increasing use as a weapon,” the document says.

The home secretary, Amber Rudd, said: “All forms of violent crime are totally unacceptable, which is why we are taking action to restrict access to offensive weapons and crack down on those who carry acids with the intent to do harm.”

The proposals relating to online sales of knives and possession and sales of corrosive substances apply to England, Wales and Scotland.

One lawyer suggested that the powers already existed under the current law that makes possession of an offensive weapon a crime. “All this consultation will do is define the offence a little more,” said Rachel Adamson of the law firm Slater and Gordon. “It may be that some courts are reluctant to call [a corrosive substance] an offensive weapon, so this might make it easier.

She said the “two strikes” proposal already existed and could be used to cover cases of possession of a corrosive substance - and that the existing sentencing guidelines were similar. “If anything, it would be better if they put it in the sentencing guidelines as an aggravating factor.”